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Summary of Significant Accounting Policies - Schedule of Fair Value of Warrant Liabilities (Details) - USD ($) | 12 Months Ended
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Dec. 31, 2019 | Dec. 31, 2018
Accounting Policies [Abstract] |  |
Fair value of warrant liabilities beginning balance | $ 39,083 | $ 1,794,396
Fair value of warrant, Exercised |  | (55,791)
Change in fair value of warrants | (26,234) | (1,699,522)
Fair value of warrant liabilities ending balance | $ 12,849 | $ 39,083

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Balance Type: | credit
Period Type: | duration

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- Definition Warrant liability. + References No definition available. + Details
Name: | MARA_WarrantLiability
Namespace Prefix: | MARA_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- References No definition available. + Details
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Namespace Prefix: | us-gaap_
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Balance Type: | na
Period Type: | duration

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- Definition Amount of expense (income) related to adjustment to fair value of warrant liability. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section 25 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=109262497&loc=d3e20148-110875 + Details
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